The present invention generally relates to an acoustic appliance and more particularly, to a musical accompaniment unit which is so arranged that, with employment of a so-called sound multiplex system recording medium in which a vocal signal of a singer or the like is recorded on its first track and a musical signal of a musical instrument for accompaniment is recorded on its second track, when a user sings, with the recording medium being subjected to reproduction, singing abilities of the user such as rhythmical feelings, degrees of bass or soprano, etc. are automatically marked for display through comparison and calculation of the above reproduced vocal signal and signal of the song sung by the user.
In one field of acoustic appliances, there has been provided a unit which is arranged to reproduce and amplify a signal of a musical instrument or the like recorded for accompaniment on a recording medium, so that when a user sings a song to the reproduced musical signal, the song is amplified simultaneously with such musical signal. The unit as described above is commonly called "a musical accompaniment unit", and has come into wide application for general home use and business use. Subsequently, such a musical accompaniment unit will be referred to as a musical performance unit hereinafter.
In one type of the recent musical performance units, there is proposed a musical performance unit equipped with a marking or rating device capable of automatically displaying abilities for expressions or singing when a user sings a song to a reproduction of a particular recording medium.
Hereinbelow, one example of a conventional musical performance unit with a marking device will be described with reference to FIG. 1 showing a fragmentary top plan view of a conventional recording medium, and FIG. 2 illustrating a construction of the conventional musical performance unit.
In FIG. 1, the recording medium 1, for which a magnetic tape is employed in many cases, has a first track 1a in which a signal of a musical instrument, a pulse signal equivalent to a musical note serving as a standard for the marking or the like is recorded, and a second track 1b in which a musical signal by a common musical instrument is recorded. Meanwhile, as shown in FIG. 2, the known musical performance unit includes a first reproducing means 2 constituted, for example, by a magnetic head 21 and an amplifier 22 for reproducing the signal recorded on the first track 1a, a second reproducing means 3 constituted, for example, by a magnetic head 31 and an amplifier 32 for reproducing the signal recorded on the second track 1b, a first amplifying means 4 constituted by a microphone 41 and an amplifier 42, and a computer 7 coupled to the first reproducing means 2, to the second reproducing means 3 through a second amplifying means 5 connected to a loud speaker 6, to the first amplifying means 4, and also to a display means 8. The second amplifying means 5 is arranged to mix the output of the second reproducing means 3 with that of the first amplifying means 4 for amplification so as to drive the loud speaker 6, while the computer 7 is adapted to drive the display means 8 through calculation and comparison between the output of the first reproducing means 2 and that of the first amplifying means 4.
Subsequently, functionings of the conventional musical performance unit equipped with the marking device having the construction as described above will be described hereinbelow.
In the first place, on the assumption that the magnetic heads 21 and 31 are respectively held in contact with the first track 1a and the second track 1b upon starting of the recording medium 1 for running or rotation, the musical signal recorded on the second track 1b is converted into an electric signal by the magnetic head 31 so as to be amplified by the amplifier 32 for being supplied to the second amplifying means 5, which drives the loud speaker 6. Consequently, the musical signal recorded on the second track 1b is amplified and converted into sound waves by the loud speaker 6. When a user sings to the music from the loud speaker 6 over the microphone 41, the output of the microphone 41 is amplified by the amplifier 42 so as to be supplied to the second amplifying means 5. As a result, mixed sound waves of the musical signal recorded on the first track 1b and the signal of the microphone 41 as amplified are produced from the loud speaker 6, and thus, the user may obtain feelings of pleasure or satisfaction by singing a song in such a manner. Meanwhile, to the computer 7, the signal serving as the standard for the markings and recorded on the first track 1a is supplied through the magnetic head 21 and the amplifier 22, together with the output of the first amplifying means 4, and these signals are subjected to the calculation processing in the digital form for display of the result of markings by the display means 8. Accordingly, levels of skillfulness for the song sung by the user may be readily found for improvements through exercises or for utilization as a game.
The conventional arrangement as described above, however, has such a disadvantage that a special recording medium must be employed for the recording medium 1. More specifically, the first track 1a of the recording medium 1 is required to be recorded with the signal or pulse signal, etc. corresponding to the musical note serving as the standard of the markings, and can not be readily prepared as desired by users in general. Moreover, in the case where a common recording medium available in the market is employed, the marking function can not be actuated. Furthermore, the user can not understand how he should sing a song in order to obtain a good marking unless the song is repeatedly sung many times.